The Atmosphere

1. The Atmosphere Chapter 12

2. Section 1 The Air around you

3. Essential Questions • What is the composition of Earth’s atmosphere? • How is the atmosphere important to living things? • What causes smog and acid rain?

4. Weather is the condition of Earth’s atmosphere at a particular time and place. • Earth’s atmosphere is a thin envelope of gases that surrounds the planet and protects it. • It is a thin layer of air forming a protective covering around the planet. (from Glencoe book)

5. Composition of the Atmosphere • Earth’s atmosphere is made up of nitrogen, oxygen, carbon dioxide, water vapor, and many other gases, as well as particles of liquids and solids.

6. What is the atmosphere made of? • It is made of gases, solids and liquids • Solids include dust, salt, and pollen • It is 78% nitrogen, 21% oxygen, and 1% other materials • It has 5 layers

7. Nitrogen • The most common gas in the atmosphere • Makes up more than ¾ of the air we breathe • Each molecule consists of two nitrogen atoms • Moves in a cycle from the air to the soil, into living things, and back into the air

8. Oxygen • Second most abundant gas in the atmosphere • Plants produce oxygen in a process called photosynthesis – they combine water, carbon dioxide, and light • Like nitrogen, oxygen moves through a cycle involving living things • Burning any fuel uses oxygen • Rust is created very slowly by steel reacting to oxygen

9. Ozone • “supercharged oxygen” • Formed from oxygen with three oxygen atoms in each molecule instead of the usual two • The ozone layer helps protect Earth from ultraviolet radiation given off by the Sun

10. Carbon Dioxide • Plants use carbon dioxide from the air to make food • Each molecule has one atom of carbon and two atoms of oxygen • Plants and animals give off carbon dioxide • Burning fuels (such as coal and gasoline) releases carbon dioxide into the atmosphere

11. Other Gases • Argon and carbon dioxide make up most of the 1% of the atmosphere that isn’t nitrogen or oxygen • Trace gases are the other gases in the atmosphere. There are only small amounts of these

12. Water Vapor • Water in the form of a gas • It is invisible (steam is tiny droplets of water and is NOT water vapor) • Each water molecule contains two atoms of hydrogen and one atom of oxygen • Very important in weather • Clouds form when water vapor condenses to form tiny droplets of water in the air

13. Particles • Solids and liquids – dust, smoke, salt, and other chemicals • Most are too small to see

14. Earth’s atmosphere as seen from space

15. What does the atmosphere do for us? • It traps oxygen close to Earth for us to breathe. • It helps keep the perfect temperature on Earth for plants and us to live. It traps energy from the Sun. • It protects the planet from harmful ultraviolet radiation from the Sun. • It protects us from space objects striking Earth (such as meteoroids – space rocks) • Because the atmosphere is constantly changing, the air can be considered a renewable resource

16. Asteroid grazing Earth’s atmosphere

17. What would life be like on Earth without the atmosphere? • During the day temperatures would rise very high and probably be too hot for life. • During the night temperatures would drop to very cold levels.

18. Air Quality • The air we breathe into our bodies may be filled with harmful chemicals and particles • Pollutants are harmful substances in the air, water, or soil • Air pollution can affect the health of humans and other living things

19. Sources of Pollution • Natural processes can add particles to the atmopshere • Forest fires, soil erosion, dust storms all add smoke and dust to the air • Wind carries molds and pollens • Erupting volcanoes spew out dust, ash, and poisonous gases • Burning fossil fuels adds carbon monoxide, nitrogen oxides, and sulfur oxides to the air

20. Smog & Acid Rain • Caused by the burning of fossil fuels • Smog = smoke + fog; a type of air pollution • Photochemical smog – formed when sunlight acts upon hydrocarbons and nitrogen oxides. It is a brown haze in the sky. • Can be harmful to plants and can irritate humans

21. Acid Rain • Rain that contains more acid than normal • Caused when water vapor mixes with harmful nitrogen oxides and sulfur oxides in the air • Can be strong enough to damage surfaces of buildings and statues • Harmful to lakes and ponds

22. Improving Air Quality • The US has many laws to protect and clean up the air • The Environmental Protection Agency (EPA) monitors air pollutants in the US • Air quality has improved because of improvements to automobiles and power plants • More cars and more power plants are needed now, so air quality still needs to improve

23. Solutions for Improving Air Quality • Use public transportation as much as possible • Stricter regulations might be needed • Could this cost too much?

24. Review Quiz • The most abundant gas in the atmosphere is • Ozone • Water vapor • Oxygen • Nitrogen

25. Quiz continued • ___________ is the condition of Earth’s atmosphere at a particular time and place. • Climate • Temperature • Weather • Ozone

26. Quiz continued • True or False: Earth’s atmosphere makes conditions on Earth suitable for living things. • Smog and acid rain can be caused from burning • Coal • Petroleum oil • Natural gas • All of the above

27. Essential Questions Answered • What is the composition of Earth’s atmosphere? 78% nitrogen, 21% oxygen, 1% other • How is the atmosphere important to living things? It holds oxygen, keeps Earth warm, and protects us from UV rays and meteors. • What causes smog and acid rain? Pollution from burning fossil fuels